Apparatus for the control of highway crossing signals



Dec. 12, 1939. k H CRAGO 2,183,161

APPARATUS FOR THE CONTROUOF HIGHWAY CROSSING SIGNALS Filed March 18, 1958 .D 17 [1/]? {v if? ya L2 I INVENTOR L Q Paul H 6 1 6190.

2.5 H15 ATTORNEY Patented Dec. 12, 1939 'lJNiiED stares imam APPARATUS FOR THE CONTROL .OF HIGH- WAY CROSSING SIGNALS Paul H. Crago, Wilkinsburg, Pa., assignor to The Union Switch & Signal Company, .Swissvale, Pa, a corporation of Pennsylvania Application March 18,

'7 Claims.

My invention relates to apparatus for the control of highway crossing signals of the type involving electric lights.

One object of my invention is to provide novel and improved apparatus iorchecking the integrity of the lamp filaments of a signal of the type described, and to cause an indicator to change its aspect if a lamp filament of the signal is not intact. Other features and advantages of my invention will appear as the specification progresses. l

I shall describe two forms of apparatus embodying my invention, and shall then point ou the novel features thereof inclaims. I

. are diagrammatic views showing two forms of apparatus each embodying my invention. Similar reference characters refer to similar parts in of the two views. Referring to Fig. 1, reference characters I and to. designate the track rails of a stretch of rail- Way which is intersected at grade by a highway H. A highway crossing signal Sv is located at the intersection. Signal S may be of any suitable type, and as shown here is of the flashing light type provided with two light units, designated by thereference characters L! and L2. The light unitsLl and L2 each have an electric lamp with a filament, and are adapted to display. a red indication when illuminated. These light units are,

according to usual practice, alternately flashed at a rate of substantially times per minute in response to the approach of a train to the crossing to simulate the appearance of a -horizontally swinging red lantern.

The operation oihighwaycrossing signal S is governed by a flasher relay NF. The flasher relay may take difierent forms, but a preferred form is that covered in United States Letters Patent Reissue No. 17,252 to C. S. Snavely and W. B. Wells on Electrical relays. Relay NF includes a pivoted armature 1c and windings 'laand'lb cooperating therewith to oscillate it about its axis when these windings are alternately energized and thereon insulated contact members 8, Sand l4. Contact member It is positioned between fixed contacts I5 and it so as to engage. contact l5- In the accompanying drawing, Figs. 1 and 1a deenergized. The armature lc has mounted.

1938, Serial No. 196,739 (or. 246- 130) and lb are deenergized. It should be pointed out that contact H is preferably constructed of suitable flexible material, thereby permitting the armature E0 to swing to the right or left of its mid position in response to the swinging of the armature lc. Contact member it when in engagementwith contact l5 shunts winding la and when in engagement with contact it shunts winding'ib. Thus, when an energizing electromotive force is applied across wires 25 and 36, winding lb is energized to attract the armature 'lc to 1'0- tate the armature in the counterclockwise direction so that contact-member M is moved out of engagement with contact 15 and into engagement with contact Hi. This movement of contact member removes the shunt on winding 'la and closes the shunt on winding lb so thatwinding lb is deenergized and winding "la is energized. The armature lo is now attracted toward winding la and contact member l4 swings out of engagement with contact l6 and into engagement with contact, so that winding lb isreenergized and winding la deenergized. This cycle of operation is periodically repeated as long as the circuit for the relay NF is closed, the parts being so proportioned that an operating cycle is completedsubstantially every two seconds or 30 times per minute. ,The contact member 8 is so positioned be tween a pair ofv fixed wiper contacts ill and H as to engage both contacts when the armature To is in mid-position. and to be moved out of engagement with first one-and then the other when the armature .lc isoscillatedin the manner 'cited above. In like manner,-the contact member 9 is so positioned between a'pair of fixed-wiper contacts i2 and L3 as to'engage both contacts when the .armatureis in mid-position and to be moved out of engagementwith first one and then the other in response to operation of the armature lc. As will shortly be described, the contacts 8|ii and 9l3 are. interposed in circuits .for the lamp of light unit L2,.and the contacts 8 i l and 9-!2 are interposed in circuits for the lamp of light unit Lt. I

The flasher relay NF is controlled by train act'u ated means which, as shown in Fig. 1, consists of trackcircuits. The track rails i and iaare divided by thel'usual insulated rail joints ,2 intotrack sections D-E and EF, the junction of the two sections being at the highway intersection H. The sections D-E and E-F, are each provided with a track circuit which in each case includes a source of current, such as a battery 3, connected across the rails at one end of thesection and a winding of an interlocking relay 1R connected across the rails at the other end of the section, the winding WI of relay IR being associated with the circuit of section D-E and the winding W2 of relay IR being associated with the circuit of section E--F. It will be understood, of course, that my invention is not limited to an interlocking relay and other forms of track relays may be used.

As shown in Fig. 1, the relay NF is supplied with direct current through the medium of a full wave rectifier I, the input terminals of which are connected across the secondary winding 3| of a transformer T; the primary winding 32 of which transformer is connected with any convenient source of alternating current, such as a generator not shown. To be explicit, the circuit for relay NF-(when contact Ifi-IB is closed) extends from the right-hand output terminal of rectifier 4 over wire 30, full down contact 5 of winding WI or full down contact (I of winding W2, wire 25, contact I4-I 5 of relay NF, winding 'Ib, and wires 36 and 38 to the left-hand output terminal of rectifier 4. With contact I4 moved to engage contact I6 in the manner described hereinbefore, the circuit is the same up to wire 25, and thence through winding Ia and contact I4I6 to the left-hand output terminal of rectifier 4. Hence, with winding WI or W2 of the relay IR shunted in response to a train approaching the highway from either direction, the relay NF is operated.

Associated with each lamp filament of signal S is a lightout relay, designated by reference character R with a suitably distinguishing numeral. Each relay R is provided with two windings II and I8, one of which, I8, has a sufiiciently high resistance so that when this winding is connected in series with the filament of the asso ciated lamp, the lamp will not become lighted. The other winding I? has a sufiiciently low resistance so that when this winding is connected in series with the filament of the associated lamp, the lamp will become lighted. The low resistance winding II of relay RI has connected in parallel with it an asymmetric unit I9, such as is used to permit a direct current relay to be energized by an alternating current source. Likewise, the low resistance winding I I of relay R2 has connected in parallel with it an asymmetric unit 34.

A first, or energizing, circuit for the lamp of unit LI passes from the top terminal of a secondary winding 35 of transformer T through back contact 28 of winding WI or back contact 2I of winding W2 of relay IR, contact 8-H of relay NF, winding I! of relay RI and asymmetric unit If! in multiple, filament of the lamp of unit LI, and wires 33 and 36- to the lower terminal of secondary winding 35 of transformer T. A first, or energizing, circuit for the lamp of unit L2 passes from the top terminal of secondary winding 35 of transformer T through back contact 20 of winding WI or back contact 2I of winding W2 of relay IR, contact 8-48 of relay NF, winding II of relay R2 and asymmetric unit 34 in multiple, filament of the lamp unit L2, and wires 33 and 35 to the lower terminal of the secondary winding 35.

A second or checking circuit for lamp LI passes from the right-hand output terminal of rectifier 4, through wire 30, back contact 5 of winding WI or back contact 5 of winding W2 of relay IR, wires 25 and 29, contact 9I2 of relay NF, winding I8 of relay RI, filament of the lamp of unit LI, and wires 33, 36 and 38 to the left-hand output terminal of rectifier 4. A second or checking circuit for the lamp of unit L2 passes from the right-hand output terminal of rectifier 4 through wire 30, back contact 5 of winding WI or back contact 6 of winding W2 of relay IR, wires 25 and 29, contact 9--I3 of relay NF, winding I8 of relay R2, filament of the lamp of unit L2, and wires 33, 36 and 38 to the other output terminal of rectifier It should be noted that the two windings II and I8 of each of the relays RI and R2 are so connected that the fluxes produced by them are in the same direction in the magnetic circuit of the relay.

An indicator, designated as I, is provided and may be positioned at any desirable place. Indicator I may take any of several suitable forms, and as shown here is a visible signal in the form of a light. The operating circuit for lamp I passes from terminal B of a suitable source of current, such as a battery not shown, through front contact 22 of relay RI, front contact 23 of relay R2 and the indicator I to the other terminal C of the source of supply.

While no train is approaching the highway H within the limits of track sections D-E or E-F, the apparatus is in its normal condition. That is, the windings WI and W2 of relay IR are energized, relay NF is inactive, signal S is dark, relays RI and R2 are deenergized, and indicator I is dark.

To illustrate the operation of the apparatus of Fig. l, I shall assume an eastbound train approaches the highway. When the train enters section DE, winding WI of relay IR is deenergized and the back contacts 5 and 23 are closed. The closing of back contact 5 completes the circuit for relay NF and that relay is operated. The closing of back contact 20 and the operation of relay NF causes alternating current to be alternately supplied to the energizing circuits for the lamps of units LI and L2, and the lamps are alternately flashed.

The integrity of the lamp filaments of signal S is checked as follows. During each period the contact 8I I of relay NF is closed and the lamp of unit LI is lighted, relay RI is energized and picked up by virtue of the half-wave pulses of the alternating current flowing in the low resistance winding I'I. During each period the contact 8-II is open and the lamp of unit LI is dark, direct current is supplied to the checking circuit for the lamp of unit LI, which circuit includes contact 9-I2 of relay NF and high resistance winding I8 of relay RI, and relay RI is retained energized. During each period the contact 8|U of relay NF is closed to light the lamp of unit L2, relay R2 is energized and picked up due to the half-wave pulses of alternating current flowing in the low resistance winding II of relay R2. During each period the contact 8III is open and the lamp of unit L2 is dark, direct current is supplied to the checking circuit of that lamp, which circuit includes contact 9I3 of relay NF and high resistance winding I8 of relay R2, and relay R2 is retained energized. With both lightout relays RI and R2 picked up, the indicator I is energized to indicate the integrity of the filaments of the lamp of signal S.

When a lamp filament is broken or burned out so that a lamp of signal S does not light, then the lightout relay associated with that filament becomes deenergized, and the front contact governed by that relay opens to open the circuit for indicator I with the result that indicator I becomes dark. This dark condition of indicator 1, when the section D-E is occupied by the train and the indicator I should be lighted, indicates Iii) that a lamp filament of signals burned'out or broken. 1

When the train 'vacates the-track section D-'E on its way past the intersection, winding W! of relay IR is energized, opening back contacts 5 and 2t and the energizing circuit for relay NF, and relay NF is deenergized. The operation of relay NF and signal S is stopped, and the relays R! and R2 are deenergized. 'The interlocking feature of relay IR prevents the closing of back contacts 63 and "2 i when the receding train enters track section E-F and shunts winding W2. When the train vacates sectionEF, winding W2 is reenergized and the apparatus is restored to its normal condition. It is clear that when a westbound train appro-aches the highway and enters the section E--F, the winding'WZ is deenergized and is released, closing back contacts'fi and 2i, with the result the relay NF and signal S are operated in substantially the same manner as explained for the eastbound train. 'When the westbound train recedes from the highway through the section D-E, the interlocking feature of relay IR prevents the closing of back contactsfi and 2H so that operation of the signal is stopped as soon as the rear of the train passes over the highway and vacates the section E-F. 1

A modified arrangement of the apparatusof Fig. 1 is shown in Fig. la, and by which latter arrangement a so-called cold-check for the 1 signal lamp filaments is obtained The apparatus of Fig. la is substantially similar to the apparatus shown in Fig. 1, except that the checking circuits for the lamps of signal S are supplied with current independently of the interlocking relay contacts ii and 6, but controlled-by. the flasher relay NF. The lightoutrelays RI and R2 are thus continuously energized over their checking circuits when relay NF is not operating, with the result that indicator I continuously displays its indication to indicate the condition of the filaments in hating condition.

It is'readily apparent that, when relay NF is not operating, ifa lamp filament becomes burned outor broken, then the lightout relay associated with that filament is deenergized to release its front contacts and indicator I becomes dark. This dark. condition indicates that a lamp filament is not intact, and that one lamp at least of signal S will not light when a train enters upon the control stretch.

The operation of the apparatus of Fig. la, When relay NF operates, is substantially similar to the operation of the apparatus of Fig. 1 when relay NF operates, inasmuch as the checking circuits of both Figs, 1 and 1a are controlled over flasher relay contacts. v It follows that in Fig. la, the checking circuits for the signal lamps serve to maintain the high resistance windings of the lightout relays energized during the darkened condition of the signal lamps, and that the first or energizing circuits for the signal lamps serve to maintain the low resistance windings of the lightout relays energized during the illuminated condition of the lamps, with the result that if both lamp filaments are intact, the indicator I is controlled by the energized lightout relays to indicate this condition.

One feature of apparatus embodying my invention is the provision of means to indicate the condition of the lamp filament of the highwaycrossing signal during the operating period of their cold or nonillumi-,

the signal, or, if desiredduring both the operating and non-operating periods of the signal,

Although I haveherein shown and described only two forms of apparatus embodying my invention, it is understood that various changes and modifications may be made therein within the scope of the appended claims without departing from the spirit and scope of my invention.

Having thus described my invention, what I claim is:

-1. In combination, a stretch of railway track intersected by a highway, a highway crossing signal located at the intersectionv al'ldCOIllDliS- ing a plurality of flashing lights each having a lamp filament, a flasher relay controlling said signal, train actuated means to operate'said flasher relay, lightout relays one associated with eachlainp filament and each lightout relay provided'with a low resistance and a high resistance winding, a first circuit for each lamp filament including a contact of the flasher relay and the low resistance winding of the associated lightout relay, a second circuitfor-e'ach lamp filament including the high resistance winding of the associated lightout relay and. a second contact the flasher relay, and means governed bysaid lightout relays to indicate the, condition f the lampfilaments of said signal.

In combination, a stretch of railway track ir"ersected by a highway, a-highway crossing nal located at the intersection and provided with two flashing lights each having a lamp filament, a flasher relay controlling said signal, a first lightout relay associated with the lamp filament of a first light of said signal, *asecond lightout relay associated with the lamp filament of a second light of said signal and each light out relay provided with a low resistance and a high resistance winding, circuitmeans including the lowr'esistance windings of the associated lightout relays'and a contact of the flasher relay to light the lamp filaments of said signal; other circuit means including the lamp filaments of said signal, the high resistance windings of the associated lightout relays and a second contact of the flasher relay to energize the lightout re 7 lays when said lamp filaments are dark; and means governed by said lightout relays to indicate the condition of the lamp filaments of said signal.

3. In combination, a stretch of railway track intersected by a highway, a highway crossing signal located at the intersection and comprising two flashing lights each having a lamp filament, a flasher relay controlling said signal, a first lightout relay associated with a lamp filament of a first light of said signal, a second lightout relay associated with a lamp filament or" a second light of said signal and each lightout relay provided with a high resistance and a low resistance winding, indicating means to indicate the condition of the lamp filaments of said signal and jointly controlled by said lightout relays, circuit means including the high resistance winding of each of the lightout relays connected in series with its associated lamp filament for energizing said lightout relays when said flasher relay relay is deenergized, train actuated means to energize said flasher relay, and other circuit means including said circuit means together with the low resistance windings of each of said lightout relays connected in series with its associated lamp filament for energizing said lightout relays when said flasher relay is energized.

4. In combination, a stretch of railway track intersected by a highway, a highway crossing signal located at the intersection and provided with two flashing lights each having a lamp filament, a flasher relay controlling said signal, train actuated means to energize said flasher relay, a first lightout relay associated with the lamp filament of a first light of said signal, a second lightout relay associated'with the lamp filament of a second light of said signal and each lightout relay provided with a high resistance and a low resistance winding, indicating means including front contacts of said lightout relays for indicating the condition of the lamp filaments of said signal, means including the lamp filaments of said signal and the high resistance windings of the associated lightout relays to energize the lightout relays when said flasher relay is deenergized, and means including the lamp filaments of said signal together with the high resistance and the low resistance windings of the associated lightout relays to energize the lightout relays when said flasher relay is energized.

5. In combination, a stretch of railway track intersected by a highway, a highway crossing signal located at such intersection and comprising two lamps each having a filament, a flasher relay, train actuated means for at times operating said flasher relay, operating circuit means governed by said flasher relay for alternately energizing each of said filaments to an illuminating condition and for alternately deenergizing each of said filaments to a darkened condition, checking circuit means governed by said flasher relay for alternately energizing each of said filaments during the darkened condition of said filaments, relay means interposed in said operating and checking circuit means, and indication means adapted to be controlled at times to indicate the integrity of said filaments when said relay means is continuously energized over said operating and checking circuit means.

6. In combination with a highway crossing signal located at the intersection of a highway with a stretch of railway track and comprising two flashing lamps each having a filament, a lightout relay for each lamp and each lightout relay provided with a low resistance and a high resistance winding, a first circuit for the filament of each lamp including the low resistance winding of its associated lightout relay, a second circuit for the filament of each lamp including the high resistance winding of its associated lightout relay, a flasher relay, train actuated means for operating said flasher relay and for controlling the energization of said first and second circuits, circuit means governed by the operation of said flasher relay for alternately energizing said first and second circuits for each lamp, whereby when said first circuit of a lamp is energized, that lamp is lighted and the low resistance winding of the associated lightout relay maintains that relay in an energized condition and when the second circuit for that lamp is energized, that lamp is dark and the high resistance winding of the associated lightout relay maintains that relay in an energized condition, and means controlled jointly by the energized condition of each lightout relay for indicating the condition of the lamp filaments of said signal.

'7. In combination with a highway crossing signal located at the intersection of a highway with a stretch of railway track and comprising two flashing lamps each having a filament, a lightout relay for each lamp and each lightout relay provided with a low resistance winding and a high resistance winding, a first circuit for each lamp of said signal including the low resistance winding of its associated lightout relay, a flasher relay effective when operating for alternately energizing said first circuits, train actuated means for controlling the operation of said flasher relay, a second circuit for each lamp of said signal including the high resistance winding of its associated lightout relay, circuit means including said second circuits for constantly energizing said lightout relays when said flasher relay does not operate and effective when said flasher relay operates to alternately energize each lightout relay only when the low resistance winding of such relay is deenergized, and ind cation means governed by said lightout relays for indicating the condition of the lamp filaments of said signal.

PAUL H. CRAGO. 

